Large meetings conducted either locally or in two separate locations with at least one of the locations involving two or more individuals can be facilitated using an audio system such as a room audio system or an audio conferencing system. Such audio systems typically include some number of wired or wireless microphones, at least one wired or wireless loudspeaker and a base station which can be connected to a local or wide area communication network. In such an audio system, microphones can operate to pick up acoustic energy corresponding to speech from a near side speaker and transmit audio signals to a base station which generally operates to provide session control and to process the audio signals in a number of ways before sending it to either a local loud speaker or to a remote audio conferencing device to be played. Among other things, the base station can be configured with functionality to amplify audio signals, to regulate microphone signal gain (automatic gain control or AGC), to suppress noise, and it can be controlled to mute an audio signal captured by one or more microphones associated with a local or remote audio system.
Audio systems that have wired microphones tend to artificially limit the seating arrangement of those who are participating in a meeting or conference call, or they can introduce a disorganized and unwanted mass of cables to the top of a meeting table. Wired microphones can be either attached to one position on a conference table (so that they cannot be moved) and connected to a base station by a signal/power cable (which can be arranged to be unobtrusive at best), or they are not be attached to a conference table and are connected to the base station by a length of cable. In the case where a microphone is attached to the conference, meeting participants are limited to sitting proximate to a microphone in order to be heard, and in the later case, while the microphone can be moved to accommodate a wider range of seating arrangements and the movement of the microphone on a table top is only limited by the length of the cable attaching it to the base station, each microphone of this type introduces a cable to the top of the meeting table, and depending upon the number of microphone in the audio system, the meeting table surface can quickly become cluttered with a disorganized mass of cables. The wire clutter and seating arrangement issues have been resolved by designing audio systems that support wireless microphones.
An audio system configured to support wireless microphones allows meeting participants the convenience of sitting in an optimal position around a conference table, thus allowing each participant to more effectively contribute to the meeting. Depending upon the role of a participant in meeting or audio conference session, they can be seated around a table or they can be free to move around the meeting room while carrying or wearing a wireless microphone. Being wireless, the microphones have to be recharged after each use or periodically as necessary, otherwise their batteries may not be charged to a level that permits them to power a microphone for the entire duration of a meeting. Wireless microphone batteries can be charged by placing each microphone into a charger base device after being used. This charger base may only function to recharge microphone batteries (DC power management function), or it may function to both recharge the batteries and have complex audio signal processing functionality such as acoustic echo cancellation (AEC) functionality, double talk detection functionality, audio gain level control to name only three. Typically, after a microphone is placed into such a charger base and the battery starts charging, the functionality in the microphone that operates to capture and process acoustic audio signals is deactivated.